Solid fuel stoking mechanism



C. H. HALL SOLID FUEL STOKING MECHANISM Aug. 19, 1952 4 Sheets-Sheet 1 Filed Feb. 27, 1946 INYENTOR CORT/1:5 H HALL ATTORNEYS lll m MN Aug. 19, 1952 H, H'A'LL 2,607,468

SOLID FUEL STOKING MECHANISM Filed Feb. 27, 1946 4 Sheets-Sheet 2 n a Q INVENTOR (oar/c5 H HALL I32 ATTORNEYS Aug. 19, 1952 c. H. HALL SOLID FUEL STOKING MECHANISM 4 Sheets-Sheet 3 Filed Feb. 2'7, 1946 u m H R Y T E m T W Y B m9 mm mm mm R ATTORNEYS 6. H. HALL SOLID FUEL STOKING MECHANISM 4 Sheets-Sheet 4 Filed Feb. 27, 1946 By I CoRr/cEH HALL MwLoc/ w /afinm ATTORNEYS Patented Aug. 19, 1952 UNITED STATES PATENT OFFICE SO LID F UEL STOKING MECHANISM Cortice Hall, Birmingham, Mich., assignor to The Timken D'etroit Axle Company, Detroit, Mich, a corporation of Ohio Application February 27, 1946, Serial'No. 650,476

13 Claims; 1

This invention relates to devices for conveying solid fuel such as coal from a fuel bin to a furnace or burner and more particularly to devices of this general type which are adapted for" use with solid fuel burners of the household or domestic type. v The problem is tomechanically transfer solid fuel from the bin to the furnace while main-.

taining the fuel in its original shape or size, that is, without comminutionand degradingso that it maintains its most efilcient size for .eflicient combustion.

In the past the general practice has been to manually transfer fuel from the binto a large hopper from where it is automatically fed to a coal burner, usually by a feed screw mechanism, There have been installations where the fuel has been mechanically transferred from the bin to the burner or to the aforesaid hopper, but these installations generally use a conventional feed screw which inherently comminutes the fuel, the degree ofcomminuation and degradation being related to the length of the feed screw from the bin to the hopper. For thisreason it isessential that the length of the feed sc'rew be held to a minimum. Another objection of the screw type of bin pick-up is that it forces thecoal towards the front of the bin.

The fuel pick-up of this invention will con vey all of the coal exposed toany part of the chain without pilingv it up. Furthermore it trav' elsunder a heavy or a deep pile of coal as easily as under a light or shallow pile; with a'resulting conservation of power. While it would be desirable to dispense with the'feed screw from the" hopper to the furnace or burnerthis has to this date been found impractical in burners ofthe underfeed type. I

Therefore the primary object o'f thisirivention is to provide an improved deviceto transmit solid fuel such as coal from a fuel bin to a furi'ialce 2. tain the pressure tol'ift' the fuel into a burner, the transferring mechanism also driving the ini-' tial-conveyor.

It isanother object to provide novel gear mechanisms for driving the two conveyors from a single power source, including a device permitting the continued operation of the screw type conveyor if the initial conveyor is out of order. j

Still another important object is the provision of a novel fuel pick up posed in a fuel bin. I

Another important object is theprovision' of a novel link conveyor tube assembly which is readily disassembled for inspection or servicing of the link conveyor and which is designed for flexibility in length for ease in installation.

A still further object is to provide a novel corn' bined conveyor tube support and securing clamp.

Another object is the provision of a novel adjustable resilient means to prevent a link type conveyor from buckling and to take up the slack resulting from normal 'wear and stress.

Still other objects of the invention will beconie apparent as the -.description proceeds in connection with the drawings wherein:

Figure 1 is a top plan view ofthe' entire mech anism.

'Figure 2 is a side e1evation of the entire mechani m shown in Figure 1'.',

Figure 3 is a sectional view substantially along line13-3 of Figure 2, with details not in the plane of the section omitted. s

Figure 4 is a top plan view, partly in section, of the gears for driving the link and feed screw conveyor.

Figure 5 isasectional view substantially along line 5-5 of Figure 4, looking in the direction of the arrows.

Figure 6 is a vertical sectional view through the link conveyor bin feed drive head and gear housing. I

Figure '7 is a view looking in the direction indicated by line (-1- of Figure 6 with parts broken away to show the link conveyor bin feed drive head. a

Figure 8 is a verticalsectional view substantially along" nae 8-8 of Figure 1, locking. in the direction of the arrows, and showing a fastening and support bracket;

Figure 8a is a vertical sectional view showing a fastening similar to that of Figure 2 5w: without a support bracket.

Figure 9 is a vertical sectional view substantially along line e==9 of Figure 1', looking in the mechanism to be dis-- 1 3 direction of the arrows and showing a coupling for joining the abutting ends of lengths of the conveyor tube.

Figure 10 is a vertical sectional view substantially along line II0 of Figure 1, looking in the direction of the arrows.

Figure 11 is a vertical sectional view substantially along line II-II of Figure l and looking in the direction of the arrows.

Figure 12 is a top plan view of the fuel pick-up mechanism.

Figure 13 is a side elevation view of the fuel pick-up mechanism of Figure 12, partly in section. 7

Figure 14 is a vertical sectional view substantially along line I4I4 of Figure 12 omitting details of the sprocket and conveyor chain but showing the slots I82 and IE3 in the fuel pick-up mechanism housing.

As shown in Figures 1 and 2, the mechanism comprises as principal elements a fuel pick-up mechanism I, a link type conveyor tube assembly 2, a bin-feed drive head and transfer device 3, a link conveyor drive gear box 4, a feed screw drive gear box 5, hopper 6, and motor 1. Besides driving the link and feed screw conveyor gear boxes 4 and 5 through a belt 8, the motor drives a fan 9 furnishing air to a burner or furnace II! which receives its fuel from the hopper 6 via a tube I I having a feed screw conveyor I2 therein. Air from the fan 9 passes through a duct I3 to the burner Ill. The fan 9, burner I6 and duct I3 do not form any part of the'invention.

The hopper 6 is generally rectangular in plan, fabricated of sheet metal. Vertical front and rear panels I5 and IS'are joined by a center portion I! '(see Figure 3) which forms a longitudinal trough in the bottom of which is disposed the screw conveyor I2. A cover plate I8 closes the top of the hopper and overlaps it as shown in Figure 1 to provide a support for the bin-feed drive head and transfer device 3. The motor I is also supported by cover plate I8. The front and rear panels I5 and I6, the center portion I1, and the cover plate I8 are welded together. The panels I5 and I6 are provided with openings through which "the feed screw I2 extends from the feed screw drive gear box 5, which is mounted on the rear panel I6, to the furnace IO.

On the front panel I5 a clean out assembly I9 (Figure 2) is mounted, having a removable section held in place as by wing nuts 2!. The cover plate I8 includes a removable section 22 adjacent the front panel I5 to provide access to the interior of the hop-per, and normally held in place by conventional means such as bolts. The fan 9 is carried by a bracket 23 which is welded to the center portion I! of the hopper.

' The bin-feed drive head and transfer device 3 comprises an upper case 24 which rests upon and is fastened to a mating lower case 25 by means of bolts 26. The outer wall of the lower case 25 to substantially cylindrical and perpendicular to the horizontal cover plate I6 upon which it rests. The top edge of case 25 lies in a plane which is inclined to the horizontal as best seen in Figures 2 and 6, so that the upper case 24 resting upon it is similarly inclined. Cast integrally with the lower case 25 is a central guide and support 21 having a central vertical bore through which passes a power take-off shaft 26 (Figure 6).

A sprocket support member or yoke 29 (Figures 6 and 7) bridges the top of the lower case 25, and is secured thereto by screws 32. The yoke 4 29 has a central opening which accommodates a bearing cage assembly 33 fastened to the yoke by screws 34. Journalled in the bearings in the bearing cage assembly 33 is a shaft 35 to which is keyed or otherwise fixed a combined gear and sprocket member 36. The axis of shaft 35 is perpendicular to the plane of the inclined top edge of the case 25, and. intersects the axis of the power take-off shaft 28. An adjustment nut 31 on the upper end of shaft 35 secures the shaft in position and provides adjusting means for a pair of tapered roller bearings 38 and 39 in the bearing cage assembly. A lock washer 43 and nut 42 lock the adjustment nut 31 in position on shaft 35.

The gear and sprocket member 36 has fixed to its lower face a bevel face gear 43 which meshes with a bevel face gear 44 splined on the upper end of the power take-off shaft 28 so that the shaft 28 drives the gear and sprocket member. The bottom of the gear 44 abuts the top of an internal shoulder 45 of the guide and support 21. The top of the support 27 is inclined parallel to the sprocket 36 and bears against a seal 46 which is seated in a groove in the bottom of the sprocket. A similar seal 4'i on the top of the sprocket 36 engages the bottom of an annular wall 48 depending from the yoke 29 and surrounding the bearing cage assembly 33, and a third seal 50 is clamped between the upper case 24 and the yoke 29. Seals 46, 41 and 56 prevent the entrance of dirt or coal into the bearings and gears.

The upper end of the conveyor tube assembly 2 connects to the drive head and transfer device 3 by inserting the free end of thetube assembly into recesses 49 formed in the outer ends of the tubular extension 52 (Fig. '7') and 53 (Figs. 6 and '7)' on the drive head 3. Bolts 54 when tightened, clamp the conveyor tube assembly 2 between the extensions 52 and 53 on upper and lower cases 24 and 25. The tubular extensions 52 andg53 lie in the same plane as the gear and the sprocket 36 and both the tubular extensions and the upper and lower cases 24 and 25 are dimensioned to provide for the passage of a link conveyor 55 into the drive head 3 via the extension 53, around the sprocket 36 and thence back into the conveyor tube assembly 2 via the extension 52. The conveyor 55 is preferably of the type disclosed in my application filed August 31, 194.4,Seria1 No. 552,920 for Chain Conveyor, of .which the present is a continuation-in-part andwhich issued September 9, 1947 as United States'Letters Patent No. 2,426,998. The conveyor engages recesses in the periphery of the upper and'lower spaced flanges 6| and 62 and on the sprocket and is driven thereby.

The sprocket rotates counterclockwise when viewed as in Figure '7 and coal carried through the extension 53 enters the drive head and transfer device 3 and is released by the flights 51 on the conveyor 55 due to :the lower level of the floor 57a of the drive head and transfer device 3 and the inclination of the sprocket 36. Teeth 66 areformed on the sprocket 36 by means of aligned spaced recesses in the'fianges 6| and 62. Each sprocket tooth on the lower flange 62 of the sprocket member 36is provided with a downwardly depending blade 58 for the purpose of raking coal or other solid fuel along the floor of the bin feed drive head and transfer device 3 to an opening 59 in the floor which is disposed directlyover an opening 60 (Figures 1 and 6) through the cover plate I8, the coal thus being discharged into the hopper 6.,

. On. the bottom of the lower case of thebin feed drive head and transfer device is provided an outwardly extending continuous flange 83. The flange 83 is engaged by. several equally spaced'clamps '64 which clamp the lower case-25 to the top of the cover plate I8 by means. of bolts 65. By loosening the bolts-85 the entire bin feed drive head 3 can .be rotated about the axis of the power take-off shaft 28 and secured in'iany one of an infinite number of positions about an arcso that the fuel pick-up mechanismv lamay be accurately placed in the fuelbin'regardless of the relation of the position'of. the fuel bin to the heatingplant. The opening .88 in the cover plate I8 .throughwhich the coal enters the hopper should thus have a greater arcuate length than the opening 59 through the floor of the lower case 25 so that the coal can fall into the hopper irrespective of the angular position of the bin feed drivehead 3. 1 v

.The bin feed drive head 3 is driven by' the motor. .I- through the belt 8 and two separate gear boxes 5 and 4 previously mentioned as the feed screw drive gear box 5 and the link conveyor drive gear box 4.

The gear box 5 which is mounted on therear side of panel I8 comprises two sectionswhich may be designated as the input section II and the output section I2 having cooperating, v:locating and securing flanges I3 and I4 through'which aligned with openings in the panel I8=for-the passage of-bolts .18 which secure :the gearbox 5 to the panel I6. A pulley 19 which is driven by the belt 8 is fixedly attached to the outer end of a power input shaft 82 (Fig.,.5) which is journalled at its outer end in a roller bearing cage assembly 83 secured by screws 84 to a protruding hollow boss 85 on the input section II and containing a dirt and oil seal 8I.- The inner endof shaft 82 is journalled in a boss 88. Integral with the shaft 82 is a worm 81 which drives a worm wheel 88 mounted for rotation on and with respect to a feedscrew drive shaft 89. I

The drive shaft 89'has one'en'djournalled in a roller bearing 92 in the input section 'II and its other or forward end portion journalled'in a roller bearing 93 in the throat I6 of the output section I2. The forward end of shaft 89'projects intothe enlarged cylindrical portion TI and is squared at 94 for driving engagement witha mating socket in the rear end of the feed screw conveyor I2 (not shown in Figure 4). A seal and battle 95 in the throat I8 prevents the entrance of dirt into the bearing 93 and gear box 5 and the loss of lubricant from the gear box. On the other end of the shaft 89 a lock nut and washer assembly 96 provides means for adjustingbear ings 92 and 93', there being a removable sealing cap 91 on the input section II by which access tothe assembly 96is'obtained.

spur pinion 98 is integral with-the worm wheel 88 and-has driving engagement with a spur gear 99'keyed for rotation with-a countershaft I82 lying in thesame horizontal plane as shaft 89'and which isjournalledat one end in a bearing I83 in'th'e-in'put section II andadjacent its-other end in a bearing I84 in the output section I2. Integral with the spur gear 99 is' 'a spur pinion I85 having a driving engagement witha spur gear I86 mounted on the feed "screw drive shaft 89"and keyed thereto for rotationthe're- 6, with.. .Thus ;theigear box .5 provides a .reduction gear whereby; the worm -IJ2 is driven. at a low speed-from the pulleyI9. c I. 4 .1

..Pow'er to the link conveyor drive gear.-boxa4 is furnished byithe gear box :5 through the coun tershaft I82 which projectslthrough the'wallof the output section 12 of gear box 5; there beingla dirt and'oil seal I8 between shaft I82 andthe wal1.-' The:-gear .box v 4-:inclu'desv a flower cup shaped section I88 (Fig. 6) havinganintegral outer bracket I89w into which bolts II2.'V. are threadedato fasten the section I88 to the front. of panel. I6. The top of the section I88 is closedvby an upper section II 3 which is fastened to section I88 bycap screws II4,-and includes an upwardly extending integral tube H5 and a downwardly extending pilot flange II6 which extends into a mating recess'inthe top of I88 to align the two sections. V

The upper end ofthe integral tube I I5 passes through the cover plate I8 and hasa mating engagement with the central bore 38 in the guide and support'2'I of the lower case 25, there being a seal I I-Bbetween the tube I I5 and the wallof'the boreiw u w a .r

"Asxshown in Figure 4 'thecup-shaped section I58 has a protruding =hollow boss II9 having a horizontal'rotary input shaft I22 journalled for rotation in spacedbearing assemblies I23 and I24; The shaft I22 passes through the bearing assembly I23 which isfastened to the boss II9 by cap wscrews I25 and includes a dirt and oil seal I28. The other bearing assembly I24 is retained against its seat in the boss I I9 by the threaded plug I21. i r

Integral withthe input shaft I22 is a worm I28 having driving engagement with a worm wheel I29 keyed to the power take off shaft 28. The lower end of the shaft 28 is journalled in a bushing I32 in the lower section I88 and its upper end, below the bevel gear 44, is journalled' in a bushing I33 in the tube I I5. The worm wheel I29 rides on athrust bearingI34. 1

Power from the 'countershaft I82 of the gear box 5 is transmitted to the-axially aligned input shaft' I22 of the gear box 4 by means of a tubular coupling I35 which is secured to the countershaft I02 bya tapered-pin I38 and to the input shaft I22 bymeans of ashear'pin I31. Theconveyor tube assembly generally indicated at. 2 extends from the fuel pick up mechanism -I to the bin'feed'drive head 3. The conveyor tube'itself is formed of two similar stamp?" ings I38 and I39 (best shown in Figures 8 and 8a), each having two substantially semi-cylindrical'portions I42 and I43 connected by an integral web I44. The portion I43 of each stampe ing is provided with an offset flange I45 extending longitudinally of the stamping which provides a seat and overlapping flap for the mating part of the portion I42 of the other stamping when the stampings are placed face to face to form parallel tubes as shown. The stampings I38 spaced distances along each length of'tubing to hold the stampings together. 'At other spaced intervals along the length of the assembly 2 the lower yokes I48 and the nuts I49 are replacedby a supporting bracket I52 (Figure 8) tosupport the tubing above the floor. The top of. each bracket I52 is threaded to receive the bolt I46 and is also shaped to conform to the bottom of stamping I39 so that the two stampings are clamped between a bracket I52 and a yoke I41 by a bolt I46. The bracket is fastened to the floor. by. any

suitable means. Theconveyor tube sections formed by the mating stampings I38 and I39 are preferably made in short lengths which are coupled together to obtain the length required in any particular installation. Couplings of the type shown at the left of the section line 9-9 of Figure 1, and also shown in Figure 9 are used to couple together the abutting ends of two lengths of tube sections. These couplings comprise a pair of identical castings I53 and I54 one of which is placed on top of the joint between the abutting tube sections and the other below, the two castings being clamped together with the tube sections clamped between them, by spaced bolts I55 passing through both castings and the web I44 of the tubing. When clamped in this manner the two castings do not touch, as is clear from the drawings, so that the abutting tube sections are adequately clamped between the castings by the bolts I55 and nuts I56. Each casting I53 and I54 has a similar recess indicated at I51 which accommodates the offset flanges I45 of the tube stampings so that the flanges are not deformed by the castings when the coupling is clamped together.

The conveyor tube assembly is horizontal except for a short length which is inclined upwardly toenter the bin feed drive head 3. An angle coupling shown cut by the section line I8III of Figure 1, and shown in section in FigurelO, is used to join the horizontal tubing to the inclined tubing. The angle coupling comprises an elbow member casting I58 having parallel passageways I59 and I68 therethrough, which at their ends are in axial alignment with the horizontal and inclined portions of the tube assembly and are also recessed so that inside surfaces of the ends of the tube assembly are flush with the walls of the passageways I59 and I68. Also, as indicated in Figure 2, the top portions of the ends of the casting I58 are cut away so that a pair of coupling castings I63 and I64 may engage the exposed ends of the tube assembly to clamp them against the elbow casting I58. The securing of the tube assembly, the coupling castings, and the elbow member casting is accomplished by means of cap screws I65 and I66 passing through the coupling castings I63 and I64, the webs I 44 of the tubing assembly, and threaded into the elbow casting I58. The coupling castings I63 and I64 are identical and are similar to the coupling castings I53 and I54 except that they are of shorter length axially of the tube assembly 2 and have only one bolt passing therethrough as is clearly shown in Figure l. The ends of the horizontal and inclined portions of the tubes extend into the casting I58 to points substantially under the inner ends of the castings I63 and I64, as indicated by the dotted lines I6I of Figure 2. V

The conveyor tube assembly is attached to the base portion of the fuel pick up mechanism I .by a half cap I61 having an integral yoke I68,

and secured to the top of a portion I69, which is integral with a base member I'15,,by cap screws I12 and I13. It is to be particularly notedthat the half cap I61 does not extend around .the tube portion I42 so that the top of the tube portion may be cut away as shown to provide in combination with an opening I14 in the top of the fuel pick up mechanism .I an aperture of sufficient length to receive the amount of coal required to load the conveyor tube assembly I.

The webs I44 of the mating conveyor tube stampings I38 and I39 are'perforatedat equally spaced points two inches apart along their length for the passage of the bolts I46, I55 etc., which secure the stampings together and to the brackets I52, couplings etc. The length of the links of the conveyor 55 is also two inches, and thus the length of the conveyor tube assembly 2 can be increased or decreased in equal increments of two inches or multiples thereof by simply adding or removing the required number of links from the conveyor and cutting the conveyor tube to length, between two of the said perforations in the webs I44. Thus the distance between bolts I55 of the coupling of Figure .9, is two inches. The length of the conveyor tube assembly 2 can thus be adjusted to meet any given condition. Because of the assembled construction of the assembly 2 it is easy to remove any one or more of the upper stampings I38 to gain access .to the conveyor 55 to repair a break therein, while the conveyor remains supported along. its whole length, as will be apparent. The assembly 2 having a conveyor of about 15 feet in length has been found to be very efficient in regard to power consumption which is about 1 watt for each foot of length. As the conveyorlengthyis' increased the wattage per foot of length will decrease since the greater part of the'wattage is consumed by the drive.

The fuel pick-up mechanism generally indicated at I is shown in enlarged detail in Figures 12, 13 and 14 and comprises the base member I15 and a mating cover member I16 secured together by conventional means such as bolts I11 extending through openings in cooperating bosses I18 on the base and cover members. Integral legs I19 on the basemember I15.supports the pick-up mechanism I at the proper level above the floor in alignment with the conveyor tube assembly 2, and bosses I88 are provided thereon throughgwhich bolts, or the like may pass to secure the base member to the floor.

The base and cover members I15 and I16.are provided with oppositely disposed internal longitudinal slots I82 and I83 which together form a track or guide for a yoke member I84, and the hollow space between the base and cover members adjacent their peripheries provides a conduit for the passage of -the link conveyor 55 therethrough. In its passage through the aforesaid hollow space the conveyor 55 passes around a sprocket I85 which is journalled for rotation about a vertical shaft I86 mounted in the spaced arms of the yoke I84 and secured by apin I81.

Integral with the base member I15, and pro- J'ecting upwardly on the-interior thereof are a pair of spaced bosses I88 and I89. Near their bottoms th bosses I88 and I89 are provided with aligned passageways respectively for a coiled compression spring I92 and a central guide I93 for the spring, integral or affixed to the yoke I84 for longitudinal movement therewith in the guide formed by slots I82 and I83. A protruding hollow boss I94 on the cover member I16 encloses the bosses I88 and I89. A conveyor tension adjustment screw I95..is

'pin'or the like. member I'1B'is attached to the base member I15.

United States Letters Patent is:

"journalle'di *for Irotatio'n within the top .portions o'f'th bosses'.I88 and'ISH'and between the'bosses "has-threaded?thereon a yoke I 96.1for movement ment screw thus moving the yoke I96; t the. left as viewed in Figure 13 to increase the tension inthe link conveyor or to take up slack therein,'and to the right to obtain the oppfls ite effect. As shownin Figure 13 'th'e'adjustment screw I95 may be inserted through a coaxial opening I91 through the wall of the boss I94; After insertion, axial movement to-the left is.prevented by the reduced end 'of the screw which forms a shoulder I98, "and m'ovementto the "right isprevented by a collar I99 afiixedto the screwbya This is done before the cover Anadjustment extension member 202 passing through opening I91 has akeyed engagement with the end of the adjustment screw I95 by a conventional means such as the tongue and roove shown at 203. 'The extension member 202 is journalled for rotation in the opening I91, and'in the "half cap I61 and secured against longitudinal movement therein'by a cotter pin 294 passing through a peripheral groove in the member. 'The forward end of the member 202 extends through an aperture in the Wall 205 of the coal bin as shown in Fi'guresl and 2 and is squared to receive a crank or the like by which means the tension of link conveyor 55 may be adjusted from a position outside of the bin.

The control circuit for motor 1- is closed in any conventional'manner as by means of a thermostat. When energized, the motor 1 drives the fan 9, thus blowing air into thefurnace I0. Simultaneously the motor, through belt 8 rotates the pulley 19 by which means the gearboxes 5 and 4 are driven to actuate the feed screw-conveyor.v I 2 and the link conveyor 55. In the event of the mechanism in the" conveyor tube'assembly tube becoming jammed, the shearlpin I31 will shear to stop thetransmission ofpowerto the gear box 4 which l furnishes power to the link "conveyor'55. The gear box 5 which drives the feedscrewconveyor]? continues in operation and the hopper-fi may be filled with fuel manual-1y so that the stokerland furnace may bekept -in operation. p r

In normal operation thesolid fuel which enters thefuel pick up mechanism I through the opening I14 in the top thereof, is conveyed to the conveyor tube assembly 2 which deposits it in the bin feed to drive head 3, where it is picked up by the blades 58 on the sprocket and dropped into the hopper 6 through the opening 60 in the cover plate I8, from'where it is delivered to the furnace by screw conveyor I2.

The invention may be embodied in other specific forms Without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the ap-' pended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of they claims are therefore'intended to be embraced therein.

What is claimed and desired to 1. A stoker mechanism for a furnace or retort be secured by comprising a hoppery-a-screwconveyor-delivering solid fuelfr-om said hopper -to the furnace; a'solid "fuel pick up mechanism adapted to be disposed in a bin; -a -conveyor tube-assembly housingan endless conveyor chain for transferring solid fuel from 1 said pick up mechanism to said hopper, said fuelpick up 'mechanism and said conveyor tube assembly forming a substantially-rigid unit;

a drive .sproketfor said-chain mounted insaid conveyortube assembly and a drive shaft mounted on said hopper coupled tosaid sprocket; and

meanslpro viding -a; swivel-connection between the conveyor tube assembly and the hopper having means-for l clam-ping it ina desired position for disposing said fuel pickup mechanism ';andsaid conveyor tubeasserriblyin any'of an infinite number of-positions about an arc'with relation 'to said-hopper.

2. A stoker mechanism for a furnace-or retort "comprising a hopper a screw conveyor delivering solid fuel -=from said hopper to the furnace; "a solid fuel pick up mechanism adapted to bedisposed in a bin and including an idler sprocket;

shaft andan ou-tputshaftconnected to said drive sprocket; and a second speed reducing gearbox aving an input shaft and two output shafts,;one

of :said output shafts from said second gearbox being connected to said screw conveyor and the "other of'said output shafts-being connected-to the input shaft of said first :gearbox; and power 'means for driving the input shaft of'said second earbox. I N v 4. In the apparatus describedin claim 2, a first speed reducinglgear box having an input shaft and an output shaft connected to said drive sprocket; a second speed reducinggearbox-havingan input-shaft and two outputshafts, one of said odtput 'sh'aftsfrom said second gear box being connectedjto said screw conveyor and the other of'said output shafts being connectedxto the input'shaft or s'aidfirst gear-box, therebeing an oveno'ad release means in said lastmentioned connection; and power means for driving the-inputsha'ft of "d'secondgear box. v

5. A stoker meehanism r r a furnace or retort comprising; a hopper; a screw conveyor delivering solid. ,niern' said hopper tothe-furnace; a solid fuel'pi'ckup mechanism adapted to be disposed in a bin; a'binfeeddrive and transfer device, said transfer device discharging into said hopper; a conveyor tube assembly; anendless conveyor housed in said assembly for transferring solid fuel from said pickup mechanism to said transfer device, said endless conveyor palssing from said pickup mechanism through a first r portion of said conveyor tube assembly to said bly being removable to provide access to said endless conveyor while, it remains supported.

6. In a stoker mechanism for a furnace or retort, a hopper, a bin feed drive head and transfer device disposed over said hopper, comprising a hollow lower case member mounted on said hopper with its upper edge in a plane inclined to the horizontal and having a substantially horizontal floor with a discharge opening disposed over said hopper; an upper case member secured to the upper edge of said lower case member; means supporting a shaft for rotation within said case members with its axis normal to the plane of the upper edge of said lower case member; a link conveyor drive sprocket mounted on said shaft; blades carried by said sprocket operable to scrape solid fuel along said floor to said discharge opening; and means for rotating said drive sprocket.

7. The mechanism described in claim 6 wherein said upper and lower case members are provided with complementary extensions forming tubular receptacles for receiving the ends of a conveyor tubular assembly, said extensions being operable to clamp the tube end of the assembly between them.

conveyor; and means forming an opening in at least a portion of the top of said cover member to permit solid fuel toenter said mechanism for removal by said conveyor.

I 10. In the apparatus described in claim 2, said solid fuel pick up mechanism comprising compleinentary base and cover members forming between them a tubular passage for said endless conveyor; means forming an opening in a portion of the top of said cover member to permit the entrance of solid fuel into said pick up mechanism; and resilient means operable to shift said sprocket to take up the slack in said conveyor.

1 1. In" the apparatus described in claim 2, said solidfuel pickup mechanism comprising complementary base, and ,cover members forming beftwee'n them a tubular passage for said endless conveyor; means forming an opening in a portion of the top of said cover member; resilient means operable to shift said sprocket to automatically take up the slack in said conveyor; and

means operable from outside the bin to control the force of said resilient means.

12. Apparatus for moving solid fuel from a bin wherein asupply of said fuel is piled to a furnace wherein the, fuel is to be burned comprising a bin feed pick up device adapted to be placed within said bin beneath the pile of solid fuel and having an apertured top for entry of fuel, a conveyortubeassembly connected at one end to said pick up device, an endless conveyor housed by said conveyor tube assembly and extending through said pick up device at said aperture so as to receive fuel entering said aperture, a relatively short screw feed assembly adapted to be connected to the furnace at its discharge end, and solid fuel transfer means between the adjacent end of said conveyor tube assembly and said screw feed assembly.

13. In a solid fuel transfer device disposed between a hopper and a conveyor adapted to discharge into the top of the hopper, a housing mounted on the top of said hopper, a power operatedconveyor drive member rotatably mounted in said housing, said housing having an aperture in its lower Wall communicating with said hopper, and a scraper blade on said drive member adapted ,to move coal deposited by said conveyor into said housing toward said aperture for discharge into said hopper.

CORTICE H. HALL.

REFERENCES CITED The following references are of record in the file of this patent:

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